Low-Voltage Ride-Through operation of DFIG-based Wind-Power generation system based on Ccrowbar action

Nowadays the grid code demands that the wind power generator possesses the ability of riding through the grid voltage dips,in order to prevent the more severe successive grid faults.To protect the converter,it is needed to limit the high inrush rotor current of doubly fed induction generator(DFIG) and provide a bypass for it via a crowbar,which is connected to the rotor windings.In this paper,a novel crowbar control strategy is proposed to limit the over current in the rotor,the over voltage of the DC bus and the transient oscillation of the electromagnetic torque.Moreover,a capacitive current is injected into the grid to assist the recovery of the grid voltage.Simulation results prove that with this control strategy the DFIG is able to ride through the more severe grid voltage dips.